1. Field of the Invention
The present invention relates to a video playback unit of one or more than plurality of videos, a delivery unit and a recording medium.
2. Description of the Related Art
First, one example of a conventional unit capable of playing back and retrieving one video will be described with reference to FIG. 25. In FIG. 25, a video playback portion 120 reads video data in order from a storage unit 110 by control of a controller 100, and outputs a screen output signal, an audio output signal and a current playback time on a display 130. Further, the video playback portion takes a length of the entire video as a playback length P and outputs it to a playback starting time setting portion 101. When the time to start a playback is set by the playback starting time setting portion 101, the playback starting time setting portion 101 outputs a setting time (q) to the video playback portion 120. When the setting time (q) is inputted, the video playback portion 120 takes the video data of recording position information in the vicinity of the setting time from the storage unit 110 and performs the playback thereof. The display 130 takes a screen output signal, an audio output signal and a current playback time and performs the displaying of the video output, the audio output and the current playback time.
Another example of the conventional unit will be described with reference to FIG. 26. This conventional example is, as shown in the drawing, constituted by a client terminal 105 as the playback unit and a server system 102 connected by a network 104, and the video data are stored in the server system 102.
The controller 100 sends a control signal to the video playback portion 120, and requests the video playback portion 120 to play back a video. The video playback portion 120 sends a video request signal (r) to a server system 102 via a network 104. The server system 102 reads the request signal (r) by a video server 103, and sends designated video data to the video server 103 from the storage unit 110. The video server 103 transmits the video data to a client terminal 105 via the network 104.
The client terminal 105 stores the transmitted video data once in a buffer 106, and transfers it to the video playback portion 120. The video playback portion 120 reads the video data and outputs the screen output signal, the audio output signal and the current playback time to a display 130. Subsequent retrieval actions by using a playback starting time setting portion 101 are the same as those of the above described FIG. 25 and, therefore, the description thereof will be omitted.
The method of setting a playback starting time (setting time (q)) for the playback starting time setting portion 101 as in FIG. 25 and FIG. 26 has conventionally used the following methods of (1), (2). (1) The method of directly inputting the playback starting time. (2) The method of taking a length of the entire video as 100% and determining a designated ratio within that length as the playback starting time.
However, since the setting methods (1),(2) of the above described playback starting time do not reveal what sort of videos are stored at which position of the video data, an user is obliged to set several sorts of times by a time code or a scroll bar and, by playing back according to those setting times, to play back his target videos. For this reason, there was a problem that the retrieval of the videos took a lot of times and labors.
Next, one example of the conventional unit for simultaneously playing back a plurality of videos is shown in FIG. 27. By control of the controller 100, the video playback portions 101 to 10n take in order a plurality of video data 1 to n from the storage unit 110, and input them to video playback portions 101 to 10n. The video playback portions 101 to 10n reads in order the video data and outputs the screen output signal, the audio output signal and the current playback time to the display 130. The display 130 takes the playback time, the screen output signal and the audio output signal and performs the display of the playback time, the screen output and the audio output.
This conventional unit has a demerit that, since a processing load corresponding to the number of video data is imposed, the number of videos to be playing back is limited when the playback processing is performed by, for example, a software.
The conventional unit for simultaneously playing back a plurality of videos and playing back from a designated time is shown in FIG. 28. For example, when a length of the entire video from the video playback portion 101 is inputted to a playback starting time setting portion 201 as a playback length, the playback starting time setting portion 201 sets a time for performing the playback and outputs the setting time to the video playback portion 101. By so doing, the video playback portion 101 sets the recording position information of the video data in the vicinity of the setting time, and takes the video data from a designated recording position from the storage unit 110 and performs the playback thereof.
The setting method of the playback starting time at the playback starting time setting portion 201 uses the following two methods:    (1) The method of directly inputting the playback starting time.    (2) The method of taking the entire length of video data as 100% and determining a designated ratio within that length as the playback starting time.
Since this conventional unit does not reveal what sort of videos are stored at which position, the user is obliged to set several sort of times and performs the playback from those times onward by way of trial so as to find his target videos and play back the videos of that target. For this reason, there was a problem that the retrieval of the videos took a lot of times and labors.
The other conventional unit includes those where the above described storage unit 110 is provided within the server system connected via a network, and the videos necessary for playback are transmitted to a plurality of video playback portions via the network. However, in the case of this conventional unit, a bandwidth necessary for the transmission of videos depends on the number of videos, there was a problem that a line for high bandwidth is necessary for simultaneous network transmission.